Recently the assurance of railroad safety is very important issue in KOREA because there are lots of changes in the railroad industries. The Railway Safety Act was established in order to cope with these changes effectively and prevent the railroad transportation accidents. According to this law, Korea Transportation Safety Authority (KOTSA) has been entrusted with 'Integrated Railroad Safety Audit (IRSA)' and has implemented the safety audit to the railroad operation agencies such as Korea Railroad (KORAIL) and the railroad facility management organization such as the Korea Rail Network Authority (KR Network). The target of IRSA is to establish the effective rail safety management system and to raise the safety level of the railroad operation and facility agencies by checking synthetically their performance of safety duties with sincerity according to the Railway Safety Act. The purpose of this paper is to improve the efficiency of IRSA by the comparative research between IRSA and other similar safety audit system. To study the efficiency of IRSA, we investigated the rail safety audit systems of EU system specially France, England where the big changes have happened for the rail operation concepts and Japan where government entity control the railroad safety. The international standards of Occupational Health & Safety Assessment Series (OHSAS 18001), Quality Management System (ISO 9001) and Guidelines for Quality and/or Environmental Management Systems Auditing (ISO 19011) are investigated.